Electric welding.



O. A. KENYON.

ELECTRl-C WELDING.

APPLICATION FILED APR. 16, 1915.

1,181,227, Patented May 2,1916.

FT Ja 7- amwmp f ATTORNEY v UNITED sTAWE OFFICE I ens-A LEN KENYPN, ormsrrnes-uron nunson, NEW 2031;.

. ELECTRIC WELDING.

To all whom it may concern.

Be it known that I, OTIS ALLEN KENYON,

" a citizen of the United States, residing at River'View Manor,Hastings-upon-Hudson, in the. county of Westchester and State of NewYork, have invented new and useful Improvements in Electric Welding, ofwhich the following is a specification.

This invention relates to electric weld: ing, and has for its object toincrease the energyeiliciency of electric arc welding.

The electrical characteristics of the are are Such that when operatedfrom a source of constant potential itis necessary to connect a ballastresistance to regulate the current so that it will tend to remainconstant. In operation, the resistance characteristics of an are areasfollows :The resistance of the arc decreases with increasing current,and increases with decreasing current, therefore with constant impressedpotential the arc is unstable and cannot be maintained. A constant andrelatively large ballast resistance connected in series with thearc'will produce a'drop of F. proportional to the current, therefore,the combination as a whole will tend toward constant current with aconstant potential, because when the resistance of the arc decreases thecurrent tends'to increase and every increase in-the current will cause agreater drop in further increase incurrent.

the ballast resistance and thus reduce the E. M. F. across the arctending to prevent On .the other hand an increase in the resistance ofthe arc will tend to decrease the'current, and a decrease in currentwill cause. less drop through ballast resis'tanceand therefore allow anincrease-in E. M. F. across the arc,

thus working against any decrease in. ourrent. The ideal condition withthe above described welding circuit is approached byincreasingindefinitely the generator E. M. F. andtheballastresistance,'that is, the greater the ballast resistance themore stable the arc.

I Economically considered the ballast re- 1 Z 'sistance method is veryundesirable because the E. M. F. consumed in the ballast resist? ance isa dead loss-and any attempt to re-' duce this loss is. a'ccompanied'by a'corre- Specification of Letters Patent.

arc.

Another system of electric supply for welding is the constant-currentsystem.

However it is only in limited use because- Patented May 2, 1916.Application filed A ril 16, 1915. Seria 1 No. 21,852

sponding sacrifice inthestability of the main line, the controllercomprising a lowresistance, or by-pass, line and an arc line in parallelwith each other and in series with the main line, and two solenoidwindings, one in series with the .arc line and the other in shunttherewith, each winding adapted to control a contact bridge when currentpasses therethrough.

In the accompanying drawings: Figure 1 is a diagram illustrating aspecial relay or controller adapted to' carry out my invention. Fig. 2is :a diagram illustrating an electric welding plant, and showing threecontrollers switched into the main line. Fig. 3 is a diagramillustrating an electric welding plant, having two main circuitsand'showing various arrangements hereinafter described.

Preferably I use a generator that will produce a constant current thatcan be adjusted by means of an ordinary field rheostat for any valuewithin the maximum limit of the machine. In Fig. 2 a generator proper G,an automatic regulator R and an exciter E are diagrammaticallyrepresented. This machine may be so designed that it will respondinstantly to changes in the resist' ance of the external circuit, andmaintain a practicall constant value of current at all times. owever anyconstant-current gencrater-may be used. r

The portable relay or controller 0 is adapted to preserve the continuityof the main circuit at all times independent of the manipulation of theare. A controller C is used. in connection with each welding arc, and isadapted to be plugged across the terminals of a switch S in the maincircuit, as

shown.

When the switch S is opened the current v is simply by-passed throughthe controller without interrupting the continuit of the circuit, theonly change being a sight increase in resistance. minal of the switch,current passes through resistance 10, Fig. 1' across bridge 11, normallyclosed by spring 12, through wires 13 and 14 to the minus side of theswitch. The path 10, 11, 13 and 14 then forms a portion of the maincircuit. When the are A is struck, current asses-from the positiveterminal of the switch through the arc line 15, and are A to line 16 andseries solenoid winding 17, through wires 13 and 14 to the minus side ofthe switch. Series winding 17 controls bridge 11 against the action ofspring 12 when current passes through said winding. It will be seen thatthe arc line 15, A, 16, 17 is in parallel with the low-resistance path10, 11. If the resistance in the low-resistance path is sufiicient tocover the drop of E. M. F in the series relay 17 and the contactresistance of the are A, there is no need of a special resistance 10,and in such case resistance 10 may be omitted.

-The current passing through the series winding 17 opens the bridge 11,thus inserting the arc line in series with the main line withoutinterrupting the continuity of the circuit, and with no change inresistance exare lengthens the E. creases, and more.andmore current isshuntcept. a slight decrease first, followed by an increase as thewelder draws his are. A shunt winding 18 is inserted in parallelwith thearc line. When sufiicient current passes through the winding 18, itcontrols bridge -19, normally maintained open by spring 20.

When a we der withdraws" from the circuit he does soby lengthenirig hisarc and as the.

. F. across it ined through the windin 18 until apoint is reached wherethe mechanical resistance of spring20 is overcome and the contact bridge19 is closed, then the current from the are passing through-the bridge19, .short circuits winding 17, and allows spring. 12

to pass direct through resistance bridge 11, and wires 13, 14,andpractica ly'shortcircuits the arc and causes it to drop out of thecircuit without interrupting the. conto close bridge 11. Thisallowsthggcurrcnt T Y tinuity thereof.

From the above description it is evident that any number (if welderswithin the E. M. F. limit of the electric machine may connect into thecircuit by trollers C, see Fig.

ob is insulated oin the ot ers; and in spe- From the positlve tor--Therefore,

' can use ma 'tem of this kind arranged for-two,

tors is shown in Fig. .3. At station 1, one

means of these con 2, as Ion as each welding cial cases two men can weldon the same job several on account of the fact that the generator may becapable of furnishing E. M. F. enough to take care of several IarcS.Supposing the; generator were capable of, furnishing E. M. F. for saysix arcs and with a liberal excess for stabilizing purposes, whenoperating with one are the welder would have available from nothing upto 300 volts, depending on how long, an are he drew. An arc of 150amperes and 300 volts would produce many times more heat than is eithernecessary or good for welding. a controller exactly the same as used inplants where a number of arcs are in operation is necessary to cut outthe are as soon' as the voltage rises to a predetermined value. In thisway the arc is automatically protected from any voltage reater than saidpredetermined amount anf has the stability inherent to the high voltage.Also it is possible to fix definite limits to the amount of heat thatcan be applied by the welder in any given case independent of thenumberof welders in circuit. The current being adjusted at the enerator isautomatically maintained at t e constant value, and the voltage whicheachwelder be set by adjusting his articular control er as for instanceby adjusting the spring 19 or the winding 18 or both.

In large installations a more flexible arrangement can be provided byusing two or more generators similar to the one abovedescribed, andrunning two or more circuits throughout the working area. A sysgen amancould weld. with the current produced by one of the generator units,'andat stayet it.

tion 2 a man could weld with current produced by a second generatorunit. At station 3 connections are shown whereby one man could weld withthe sum of the currents from both the generators At station 4:connections are shown wherebyr two men can weld on the same piece, eachusing current from a difi'erent generator.

be current in each generator may be set at any value desiredeachindependent of the other. If both enerators are set at .the same value,then t ere are two values of current always available in the 'shop, thatof. one machine and double. If the machines are set at different values,there are three valuesalways available, that of each machine and the sumof the two. A perfectly flexible adjustment of the current taken b eachare independent of'all 'others may he attained by an adjustable shunt21, across the the circuit and that required at the particularcontroller where it is installed;

.7 The circuits may be increased to any'de sirednumber by adding moremachines to the plant. An'installation of" two or-more generators, suchas shown inrFig. '3, economically considered, is cheaper, in first costthan an installation of the constant-poten-' tial type capable of doingthe same amount of work, and the cost .of operation of such a plant isvery much less on account of the complete elimination of ballastresistance. Generators of this type may be connected in parallel andwhen so connected will op-.

h -erate as one machine for a constant current, independent of the valueof reslstance inseries'up to the E. F. limit of the machine.

The controllers herein described have been used by me onconstant-potential circuits of an arc. For instance, it is ordinaryprac- I current circuits.

themain circuit suflicientlyuniform to 'pre-. vent the interference-ofany. one are with any of'the others. 1

for limiting the voltage across the arc and for operatlngtwo or morearcs in series; therefore, while the. controller is especially adaptedfor use in-constantcurrent circuits it may also be advantageouslyemployed on constant potential circuits of higher voltage than thatrequired for successful operation ties to employ generators of from 60to 7 5 volts in constant-potential welding plants, while with thecontrollers of the type herev described it is possible to operate'twoarcs in series from the ordinary 125-volt lighting circuits, thusavoiding entirely the necessity of installing a. special weldinggenerator. -When-'220 volts" are-available more arcs may be operated inseries in the same manner.

Therefore,-it should be distinctly understood that'the controller hereindescribed is not in any way limited to application on constant- 7 Nordo- I limit myself to the specific form of controller, which is hereinset" forth only as the preferable means for accomplishing the. desiredresult.

' I claim as my invention:-'-

1. In el'ectric,welding, a 'main circuit, a

plurality of welding arcs adapted to be connected in series in said main"circuit, and means formaintaining the conductance of pluralityofwelding arcs adapted to be connected in series in said main circuit,means 1 others, and means for limiting the impressed volta e.

.3. 11' electric welding, a main circnit, a

.mined amount.

plurality of welding arcs adapted to be" connected in series in saidmain circuit, means for maintainmg the conductance of the main circuit'sufiiclently unlform to prevent the interference of'any one are withany of the others, and automatic means for limitingthe impressedvoltage.- p

at. In electric arc welding, a main line,

an arc line connected in parallel witha portion' of the main line, incombination with ,means adaptedtojopen the main line between theconnections of the arc line when the arc is struck, and to close themainline before the resistance in the arc line reaches .a predeterminedamount.

- 5. In electric arc welding, a main line, an

arc line connected in parallel with a portion of the main line, incombination with means the arc is struck, and to automatically close themain line beforethe resistance in the arc line reaches a predeterminedamount;

. 6. In electric arc welding','a main line, an arc line connected inparallel with a portion v of the main line, in combination withelectro-responsivemeans for. opening the main line when the arc isstruck, and to shunt the current from thearc line to the mainline when.the resistance an the arc line reaches a redetermined amount.

' In electric arc .vlxelding, a main line, an

arc line connected in arallel with a portion of the main line, a se resrelay in the arc line adapted to open the, main line between theconnections of the arc, line when the arc is struck, anda shunt relay inparallel with the arc line and ada ted to short circuit the seriesrelay-to permit the main line to close when-the resistance in'the arcline reaches -a predetermmed amount.

'8. In electric arc welding, a main line, in combination with a.controller adapted to be switched into the main line, said controllercomprising two lines. in parallel with each other and each in serieswith the main line, the first line in the controller being normallyclosed, the second including the welding arc,- and means for opening thesaid first line when the arc is struck and for closing thefirst linebefore the resistance in the 'arc line reaches a predetermined amount.

. Y 9. In electric arc welding, a main line, in combination with acontroller adapted to be switched into the main line, said controller 2.In electric welding, a maincircuit, a. i

comprising a low resistance line normally closed in series with the mainline, an arc line inseries with the main line, and means dependent uponcurrent in thearc line to open the low resistance line, andmeans forshunting the current from the arc line when the resistance therein 'ieaches a predeter- 10. In electric arc welding, a main line,

a controller adapted to be switched into 4 the main line, saidcontroller comprising a low resistance line normally closed in serieswith the said main line, an arc'line in series with the main lineandprovided with a series relay adapted to open the low resistance linewhen the arc 1s struck, and a

